Chicago, Dec. 24 (Reuters): Eating fish as infrequently as once or twice a month reduces the risk of the most common type of stroke by almost half, researchers said today.

Fish contains Omega-3 polyunsaturated fatty acids that enhance blood flow and help prevent formation of the blood clots and blockages that cause most ischaemic strokes.

“Men who consumed fish two times a month or more had almost half the risk of stroke as compared with men who never ate fish,” said study author Dr Alberto Ascherio of the Harvard School of Public Health.

“There seemed to be no benefit in eating fish very frequently, so eating fish just a few times every month was just as good as eating fish almost every day,” he said. “Our study didn’t look at the specific type of fish. We can only conclude that eating fish in general is likely to be beneficial to prevent stroke.”

The study published in the Journal of the American Medical Association involved more than 43,000 men who were between 40 and 75 years old at the start of the 12-year survey in 1986.

A total of 608 participants suffered strokes, 377 of them ischaemic strokes, where blood clots or arterial blockages cut off blood flow to a part of the body, often the brain, starving it of oxygen.

The study found those who consumed just one to three 5-ounce portions of fish every month cut their risk of ischaemic stroke by 43 per cent. Those who ate fish five or more times per week only enjoyed a slightly enhanced benefit.

Fish in the diet did not have any apparent impact on the risk of haemorrhagic stroke, in which a blood vessel bursts and bleeds into the brain.